import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

public class GetSessionServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 从请求对象中获取Session
        HttpSession session = request.getSession();
        // 从Session中获取数据
        Object username = session.getAttribute("username");
        // 打印数据
        System.out.println(username);
    }
}
